Recent efforts to decrease energy consumption and greenhouse gas emissions have resulted in sustainable, intelligent districts with energy-efficient buildings, distributed multi-energy generation systems, and alternative transportation approaches. However, there is usually slight or no coordination between the district planners and the distribution system operators. Most attention is paid to the district's annual load and generation without considering the electrical distribution network impacts. The paper presents an approach that embeds heating, cooling, several households, office appliance, and distributed generation load profiles to investigate the opportunity given by integrated planning and operation of new urban districts with distribution networks. The model has been applied to the decommissioned Farini railway yard in Milan, considering five scenarios with different electrical appliances, Combined Heat and Power (CHP) plants, and Photovoltaic (PV) systems. Several district load profiles are simulated and their influence on local distribution networks is investigated by considering different demand and distributed generators (DGs) production. Preliminary results show promising opportunities both for end-users and utilities.